The answer to 'hydro jetting overflowing' is that hydro jetting can sometimes cause a backup or overflow in the plumbing system. This is typically due to a blockage or obstruction that the high-pressure water dislodges, which then gets pushed back up through drains or fixtures.
Common causes of hydro jetting overflows include tree roots, built-up debris, or a collapsed pipe section that the jetting couldn't fully clear. Symptoms may include water backing up in sinks, tubs, or toilets, or sewage spilling out of floor drains. In some cases, the overflow may be accompanied by foul odors.